Hydraena infoveola, Perkins, 2011

Perkins, Philip D., 2011, New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944, Zootaxa 2944 (1), pp. 1-417 : 42-43

Hydraena infoveola , new species

( Figs. 54 , 56 , 438 )

Type Material. Holotype (male): Gulf Province: Marawaka , Mala, elev. 1400 m, 7° 5.664' S, 145° 44.467' E, 11 xi 2006, Balke & Kinibel ( PNG 90) ( ZSM) . Paratypes (27): Gulf Province: Same data as holotype (25 MCZ, NHM, NMW, PNG, ZSM); Marawaka, near Ande, elev. 1000 m, 7° 3.598' S, 145° 44.375' E, 10 xi 2006, Balke & Kinibel ( PNG 89) (2 ZSM) .

Differential Diagnosis. Among members of the Foliobba group, most similar in dorsal habitus to H. striolata ( Figs. 51 , 54 ); differing therefrom by the larger size (ca. 1.58 vs. 1.43 mm), the testaceous color bands in front of and behind the pronotal fascia (brown in H. striolata ), the proportionally larger pronotal fascia (color band ratios ca. 6/18/3 vs. 6/14/3), the absent, or nearly imperceptible pronotal foveae PF2, and the more widely separated metaventral plaques. Males of the two species are additionally differentiated by differences in the shapes of the tibiae, and by the striolate area on the fifth abdominal ventrite of H. striolata . The aedeagi of the two species distinctively differ ( Figs. 53 , 56 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.58/0.68; head 0.23/0.38; pronotum 0.38/0.48, PA 0.42, PB 0.42; elytra 1.00/0.68. Dorsum of head piceous; pronotum testaceous in front of and very narrowly behind piceous fascia, ratios of color bands, as measured in midline, ca. 2/3/1; elytra dark brown; legs and maxillary palpi brown.

Frons punctures ca. 1xef; interstices shining, 1–3xpd. Clypeus microreticulate laterally, very finely sparsely punctate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge. Pronotum cordiform, median 2/3 of anterior margin emarginate; punctures on disc ca. 1xpd those of frons, interstices shining, 2–3xpd, punctures slightly larger and denser at anterior and posterior; PF1 absent or obsolete; PF2 extremely shallow, nearly imperceptible; PF3 moderately deep; PF4 absent.

Elytra with summit of posterior declivity at or very near midlength; lateral explanate moderately wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, shining, on disc ca. 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect weakly separately rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 4/2/7/5. P1 laminate; median carina sinuate in profile. P2 raised, l/w ca. 2/1, sides slightly converging toward apex. Plaques moderately wide, converging very slightly anteriorly, weakly raised, slightly more so laterally than medially, located at sides of deep median depression. Metaventrite with short low ridge extended from each mesoventral coxal cavity. AIS width at straight posterior margin ca. 1.5x P2. All legs long and very slender. Profemur (male) with small, sharply pointed tubercle next to trochanter; protibia slightly arcuate, gradually increasing in width from base to apex, with moderately long spine on medial surface at ca. distal 2/3. Mesotibia moderately arcuate, ca. to same degree as protibia, slightly thickened at distal 2/ 3. Metatibia very slightly arcuate, gradually increasing in width from base to apex, medial surface, with few moderately long spines in distal 1/4. Abdominal apex symmetrical; last tergite (male) deeply notched. Aedeagus ( Fig. 56 ) distal piece with sharply pointed, slightly arcuate process on left side, and large, arm-shaped process apically.

Etymology. Named in reference to the greatly reduced and absent pronotal foveae.

Distribution. Currently known only from two very narrowly separated sites near Marawaka, at the eastern extreme of Area 1; elevations 1000 m and 1400 m ( Fig. 438 ).

Figures

FIGURE 51. Hydraena striolata, holotype, dorsal and lateral habitus, venter, and abdominal apex.

FIGURE 54. Hydraena infoveola, holotype, dorsal and lateral habitus, and venter.

FIGURES 56–57. Aedeagi of holotypes. 56. H. infoveola. 57. H. otiarca.

FIGURES 435–438. Geographical distributions of Hydraena species.

FIGURES 52–53. Aedeagi of holotypes. 52. H. foliobba. 53. H. striolata.